Pneumatic structure



May 16, 1950 M. J. STURTEVANT PNEUMATIC STRUCTURE Filed Nov. 20, 1944 "the Patented May 16, 1950 PNEUMATIC STRUCTURE Mark J. Stur-tevant, Akron, Ohio, assignor to Wingfoot Corporation; Akron, Ohio, a corporation of Delaware Application November 20, 1944, Serial No. 564,304

3 Claims. I

The present invention relates to pneumatic structures generally of the type embodying a. plurality of individually inflatable fluid compartments; More particular-lathe invention pertains .to-thoseforms of pneumatic structures which are characterizedbyat least apair of individually inflatable cells which are advantageously flexible and fabricated from rubberized fabric or the like, ,sa'idzcellsbeing disposed in cooperating relation so as to form therebetween afluid-tight enclosure.

The teachings of thepresent invention are particularly advantageously adapted to be'employed in theconstructionof life. vests, inflatable rub- (her boats and-other similar pneumatic structures. The arrangement of the elements of the pneumatic structure is such that each pair of inflatable cells or compartments comprising the v-structu-re is of generally similar configuration and is adapted to be disposed in substantially superposed relation to form therebetween an enclosure which may also be inflated. The inflation of this intermediate enclosure operates to increase the buoyancy of the structure materially and supplements the lifting action of the adjacent cells.

it is an object of the present invention to provide apneumatic. structure which. aifords a materially increased buoyant effect to the apparatus with which it is employed.

It is a'furthenobject ofth'e present invention to provide an arrangement of inflatable compartments and intermediate enclosure associated therewith wh-ich-willafiord the desired additional buoyancy with virtually no increased weight in the structure.

It is a still further-object of the invention to 7 provide a form of pneumatic structure -in which inflation of the substantially superposed compartments automatically achieves at least partial self-inflation of the: intermediate enclosure.

Another and still further object; of. the present inventienis to provide a teaching which; when applied to suitable: pneumatic structures; will impart an: additional factor of safety tothose devices With which it is employed.

It is another object of the present invention to providea pneumaticstructure'which not only will achieve increased lifting advantage but will also be capable ofbeing cheaply and easily f-abricated, inasmuchas it represents little, if an in:- m'eased'manufact "ring cost and requires only an extremely small outlay of. additional. material beyond that of conventional structures.

Although the principles of the invention are broadly applicable to pneumatic structures generally, the invention is particularly advantageously adapted to be employed in the fabrication of life vests 'andhence-it has been so illustrated and will be so described.

Figure 1 is a front elevation of a typical form of life vest embodying the teachings of the present invention. Figure2 is a side elevation of the structure illustrated in Figure 1. Figure 3 is a horizontal cross section taken along the line 33 in Figure 2 on a slightly enlarged scale illustrating the internal construction of the pneumatic structure. Figured corresponds generally to the cross section illustrated in Figure 3 but shows the vest in collapsed form;

.In Figure 1 of, the accompanying drawings, the pneumatic structure, in this case a life vest, indicated generall'y'by the reference character I embodies the principles of the present invention. The life vest l comprises a pair of individually inflatable fluid compartments 2 and 3 which are substantially identical in their configuration and arranged in substantially superposed relationship. lilachof the compartments 2 and 3 is substantially horseshoe-shaped and is formed from a plurality of plies of rubberized fabric which impart lightness and a certain degree of flexibility to the structure, particularly when it is inflated and ready for use.

The cell or compartment 2 of the life vest I is formed between plies 4 and 5 of rubberized fabr-ic material which are adapted to be spaced apart over at least a portion of their length and joined at points thereon identified by the reference char- :acter 6 adjacent the ends thereof to form a twoplywall portion. The joint 6 is reinforced over its entire length byv a crotch tape 1 which enables the plies 4 and 5 to be flexed at the joints 6 without separation. The cell or compartment 3 is substantially identical in its construction to that of the compartment 2 as is readily apparent from Figures 3 and 4 of the drawings.

The two-ply wall portions formed at the edges of the compartments 2 and. 3 and extending be yond the joints 6v are adapted to be butted and cemented or otherwise suitably secured together. A reinforcing tape 8 extends about the entire outer periphery along the butt joint between the fabric parts embodying inner and outer plies 4 and It so as to form between adjacent plies 5 of the compartments 2 and 3 an enclosure It. It will be understood from Figure 1 of the drawings that the compartments 2 and 3, when joined together in the manner hereinbefore described, form continuous compartments extending from end to end of the vest I together with the continuous enclosure l therebetween.

The compartments 2 and 3 may advantageously be provided with internal webs 9 which are formed of some suitable substantially inextensible material adapted to prevent excessive bulging or ballooning of the compartments when they are inflated. The webs 9 are illustrated in Figure 3 in their extended position and in Figure 4 in folded or creased relationship when the compartments in which they are disposed are deflated. It will be understood that these webs 9 may be so disposed that they perform the desired function without in any way obstructing the passage of the fluid with which the compartments in which they are disposed are inflated. Thus, a space may be provided about either end of the webs S to insure positive overall inflation of the compartments.

The compartments 2 and 3 of the vest I may be inflated in any of several different ways, the use of carbon dioxide gas being perhaps the most advantageous method of inflation. To this end, the cylinder H is affixed to a tubular connecting means 12 projecting through the outer wall of the fabric ply 4 which cooperates with the ply to form the compartment 3'. The cylinder H is provided with a threaded cap l3 which seals an open end of the cylinder in which may be inserted a suitable carbon dioxide bulb (not shown) which will be punctured by the actuation of a lever arm [4 pivotally mounted in the bifurcated end portion 5 at the opposite end of the cylinder H from the cap l3 when the cord it attached to said arm H3 is pulled.

The fluid released from the punctured gas bulb passes through the connecting means [2 to the interior of the compartment 3 inflating it completely from end to end. A similar cylinder H may be attached to the connecting means I! extending through the outer ply 4 and associated with the compartment 2 of the life vest l in order that this compartment may be inflated in a manner similar to that employed in the inflation of the compartment 3.

An additional stub connection [8 disposed adjacent the collar portion is of the life vest l is provided in the outer p-ly t to enable the attachment thereto of a conventional valve means of the manually operable thumb screw type. The valve means 29 is provided with a rubber tube 2| attached to one end thereof rendering it possible to orally inflate the compartment 3. Such an operation may become necessary or desirable by reason of the failure of the other inflating means to provide sufiicient buoyancy or the loss of buoyancy by the gradual diffusion of the inflating fluid through the fabric walls. A similar stub connection 22 connected with the compartment 2 of the life vest i may be provided with an identical valve member 2e and inflating tube 2! to that previously described.

The life vest l is adapted to be Worn about the neck and across the shoulders and chest of the wearer with the collar portion is fitting snugly around the neck. The cross straps 23 attached at one end thereof adjacent the collar portion i9 and at their opposite ends to the lowermost ends of the projections 24 are adapted to flt across the back and shoulders of the wearer and to maintain the vest in place. To facilitate the donning of the vest, a pair of straps 25 attached to the innermost edge of the projecting portions 2 of the vest I are provided. The straps 25 are adapted to be connected by means of disenenclosure.

gageable snap fasteners 25 to hold the vest I in place across the chest of the wearer.

The pneumatic structure of the present invention, as embodied in the life vest I, is particularly advantageous for the reason that upon the inflation of the compartments '2 and 3 an internal pressure is created within the enclosure ill between the compartments which is normally lower than the external atmospheric pressure. This negative pressure in the enclosure enables air to be drawn through the connection 21 provided on the exterior of the vest which communicates with the enclosure It) to at least partially inflate the This connection 21 is also provided with a valve 28 which is generally similar to the conventional valve 29 hereinbefore described and is fitted with a tube 29 for additional oral inflation of the enclosure l6, if it should be desired.

During inflation, the compartments 2 and 3 attempt to distend themselves to a substantially cylindrical form but are restrained from so doing the some extent at least by the internal webs 9. lhe general shape assumed by the compartments 2 and 3 is illustrated in cross section in Figure 3. The enclosure it which is actually of the shape shown in Figure 4 thus temporarily takes the form of a centrally disposed longitudinal passage HJa, communicating with adjacent secondary passages Nib. The negative pressure created in the passage liia of the enclosure IE1 causes air to be drawn or sucked into the enclosure when the valve 28 is opened.

Although the operating conditions are obviously dependent upon the characteristics of the particular pneumatic structure, a typical vest of this type will have a buoyancy of about 21 pounds when the compartments are inflated. When the valve 23 controlling the admission of air to the enclosure H3 is opened, sufficient air will be sucked into the vest structure to increase the buoyancy to aproximately 23 pounds. The enclosure l0 may be orall inflated to an extent such that the maximum buoyancy of the vest will range from 29 to 32 pounds.

The enclosure 55 thereby afiords a very advantageous means of providing a substantially increased buoyant efiect to the pneumatic structure suplementing that produced by the generally superposed compartments 2 and 3. The provision of the tube 29 and its disposition with respect to the collar portion IQ of the vest l is such as to permit oral inflation by the wearer when the vest is in use and whenever it may be necessary to provide additional buoyancy.

Moreover, the enclosure H3 incorporates in the vest I an additional margin of safety in that it will supplement the normal buoyant efiect of the compartments 2 and 3. In the event that one or both of the compartments 2 or 3 should be punctured or otherwise damaged, it will additionally replace the damaged cells in maintain ing the wearer afloat. When a compartment is punctured the ply 5 will collapse against the ply 4 thereby enlarging the enclosure Ill to completely replace the previously inflated compartment.

It will be understood that certain minor changes and modifications may be embodied in the pneumatic structure without in any way departing from the spirit or scope of the invention. For instance, the oral inflating tubes 2|, valve means 29 and stub connections l8 and 22 for the compartments 3 and 2, respectively, may be eliminated. Thus, the compartments 2 and 3 are inflated solely by the gas cylinders H and 5 the enclosure l alone is capable of oral inflation.

The design of the vest I may be also modified to enable both gas cylinders II to be mounted on the front or outer side of the vest. This can be accomplished by foreshortening the outermost one of the compartments with respect to the body of the wearer, compartment 3 in the illustrated embodiment, to permit the connecting means ll associated with the innermost compartment 2 to extend into and connect directly with this compartment. This foreshortening of the compartment 3 is provided only adjacent the left hand lobe or projecting portion 24 as seen in Figure 1. To provide balanced inflation of the compartments 2 and 3, the compartment 2 may be similarly foreshortened adjacent the right hand lobe or projecting portion 24 (Figure 1).

By virtue of the superposed disposition of compartments 2 and 3, the vest l assumes a shape in cross section closely approaching a rectangle. This feature is particularly advantageous for the reason that the vest fits snugly about the neck of the wearer and does not obstruct the movement of the arms for swimming.

The spaced plies 4 and 5 forming each compartment 2 and 3 affords a double wall of fabric to reinforce the internal enclosure l0 and minimize danger of damage thereto. The butted ends of the joined plies enclosing the compartments cooperate with the reinforcing tape 8 to protect the ends of the enclosure I0 against puncture and rupturing.

The same principle as applied herein to the life vest I may also be employed in life rafts, many forms of inflatable rubber boats as well as to other similar structures to provide a materially increased buoyant effect in the structure and to afford an additional factor of safety in the event that any one or more of the fluid compartments should become damaged or deflated either before or after their inflation.

While in accordance with the patent statutes one best known embodiment of the invention has been illustrated and described in detail, it is to be particularly understood that the invention is not limited thereto or thereby, but that the inventive scope is defined in the appended claims.

I claim:

1. A pneumatic structure comprising a first inflatable walled compartment embodying two flat superposed plies of substantially fluid impervious material which are joined together to form a joint adjacent their edges and to leave a marginal portion of at least one ply projecting beyond the joint and extending about the entire periphery of the plies; a second inflatable walled compartment constructed in the same fashion as the first superposed thereon; a substantially fluid impervious means joining the marginal portions of the two superposed walled compartments to form a substantially fluidtight enclosure therebetween; and individual inflating means connected to each compartment and to the enclosure.

2. A pneumatic structure comprising a first inflatable cell embodying two flat superposed plies of substantially fluid impervious fabric which are joined together to form a joint adjacent to but spaced inwardly from the edges of the flat fabric plies leaving a marginal portion projecting beyond the joint and extending about the entire periphery of the fabric plies, said joint being reinforced by a crotch tape which is coextensive therewith; a second inflatable cell of identical construction to the first superposed thereon; a strip of substantially fluid impervious fabric joining together the marginal portions of the two superposed cells to form a substantially fluid-tight enclosure between the cells; and individual inflating means connected to each cell and to the enclosure.

3. A pneumatic structure comprising a first inflatable cell embodying two flat superposed pieces of rubberized fabric which are joined together to form a joint adjacent to but spaced inwardly from the edges of the fabric pieces with a marginal portion of at least one of the fabric pieces extending beyond the joint about the entire peripheral dimension of the fabric pieces, a crotch tape reinforcement secured to the contiguous surfaces of the fabric pieces at the joint formed therebetween, and a web member connecting portions of the contiguous surfaces of the fabric pieces intermediate the edges thereof; a second inflatable cell substantially identical to the first cell disposed in directly superposed relation to said first cell; a strip of rubberized fabric secured to and joining together the marginal portions of the superposed cells to form a substantially fluid-tight enclosure therebetween; means inflating each of the cells; tubular means on each cell independent of the inflating means for the individual inflation of the cells; and similar tubular means connected to the enclosure for. its inflation.

' MARK J. STU RTEVANT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,042,327 Costanzo Oct. 22, 1912 1,733,034 Tufenkjian Oct. 22, 1929 FOREIGN PATENTS Number Country Date 420,737 Germany Oct. 30, 1925 

